{"id":4269,"date":"2021-06-08T06:49:11","date_gmt":"2021-06-08T10:49:11","guid":{"rendered":"https:\/\/www.chaneyhealth.com\/healthtips\/?p=4269"},"modified":"2021-05-22T17:56:23","modified_gmt":"2021-05-22T21:56:23","slug":"is-the-paleo-diet-based-on-a-myth","status":"publish","type":"post","link":"https:\/\/www.chaneyhealth.com\/healthtips\/is-the-paleo-diet-based-on-a-myth\/","title":{"rendered":"Is The Paleo Diet Based On A Myth?"},"content":{"rendered":"

Are Starchy Foods Bad For Us?<\/strong>\u00a0<\/strong><\/span><\/h2>\n

Author: Dr. Stephen Chaney<\/strong><\/p>\n

\"the<\/a>The Paleo Diet is still very popular. And it does have its good points. It is a whole food diet. It eliminates sodas, junk foods, and highly processed foods. Any diet that does that can\u2019t be all bad.<\/p>\n

But is it unnecessarily restrictive? It eliminates starchy foods like grains, beans, peas, and corn. It is true that widespread consumption of these foods did not occur until after the agricultural revolution some 12,000 years ago. Our paleolithic ancestors probably did not consume significant quantities of these foods.<\/p>\n

But did they consume other starchy foods? Our ideas about this have come primarily from comparing the diets of modern man with the diets of the few primitive hunter-gatherer populations that currently exist in our world. Based on that comparison, some Paleo advocates have concluded that the paleolithic diet contained few, if any, starchy foods.<\/p>\n

More importantly, some Paleo advocates have gone a step further to assert that our bodies are not designed to eat starchy foods. They claim that foods like grains, legumes, corn, and potatoes are bad for us. They should be avoided.<\/p>\n

How can we test whether these claims are true? After all, we don\u2019t have any way of directly determining whether our paleolithic ancestors ate starchy foods or not. Or do we? That question is the topic of a new study (JA Fellows et al, PNAS, 118 No. 20 e2021655118<\/a> I will share with you today.<\/p>\n

But first I need to acquaint you with what starch is and how we digest it. Once again, it is time for Biochemistry 101.<\/p>\n

Biochemistry 101<\/strong><\/span><\/h2>\n

\"professor<\/a>Starch is simply a long polymer of glucose molecules. Digestion of starch starts in our mouth. Our saliva contains an enzyme called alpha-amylase that breaks the bond between adjacent glucose molecules. Alpha-amylase breaks starch down sequentially, first to maltodextrin (a shorter polymer of glucose molecules), then to maltose (two glucose molecules), and finally to glucose.<\/p>\n

[Note: The nutrition gurus that tell you to read labels and avoid foods with maltodextrin are ignoring the fact that we produce maltodextrin naturally whenever we digest starch in the foods we eat.]<\/p>\n

All humans contain the alpha-amylase gene. Simply put, that means that all humans have the potential to digest starchy foods. <\/strong><\/span><\/p>\n

However, not all humans have the same number of copies of the alpha-amylase gene. When we habitually consume a diet containing starchy foods, our bodies duplicate the alpha-amylase gene until our saliva contains enough alpha-amylase to easily digest the amount of starchy foods we are consuming. Simply put, that means our bodies are designed to easily adapt to the amount of starchy foods in our diet.<\/strong><\/span><\/p>\n

Most modern human populations have between six and 30 copies of the alpha-amylase gene. Our saliva contains a lot of alpha-amylase. However, the few primitive hunter-gatherer societies that still exist in our world have only two or three copies of the alpha-amylase gene. Their saliva contains very little alpha-amylase.<\/p>\n

It is this difference that has led to the hypothesis that our paleolithic ancestors did not possess salivary alpha-amylase, which implies they didn\u2019t eat starchy foods. This hypothesis also assumes that humans only began producing significant quantities of salivary alpha-amylase after the agricultural revolution when starchy foods like grains, rice, and beans became widely available.<\/p>\n

This hypothesis is one of the central tenets of the Paleo diet. But we need to remember that it is just a hypothesis. It has not been directly tested because we thought there was no way to determine the starch content of the paleolithic diet \u2013 until now. However, before we get to the study that explodes this hypothesis, I want to revisit the Paleo Diet myths I described in an earlier issue<\/strong><\/a> of \u201cHealth Tips From The Professor\u201d. I call this next section \u201cUnicorns And The Paleo Diet\u201d.<\/p>\n

Unicorns And the Paleo Diet<\/strong><\/span><\/h2>\n

\"the<\/a>I titled this section \u201cUnicorns and the Paleo Diet\u201d because both are myths. In fact, the Paleo Diet is based on several myths.<\/p>\n

Myth #1<\/strong>: Our ancestors all had the same diet.<\/strong><\/span> What we currently know as the Paleo diet is based on the diets of a few primitive hunter-gatherer societies that still exist in some regions of the world. However, when you look at the data more carefully, you discover that the diet of primitive societies varies with their local ecosystems.<\/p>\n

The \u201cPaleo diet\u201d is typical of ecosystems in which game is plentiful and fruits and vegetables are less abundant or are seasonal. In ecosystems where fruits and vegetables are abundant, primitive societies tend to be more gatherers than hunters. They eat more fruits and vegetables and less meat.<\/p>\n

The assumption that starchy foods were absent in the paleolithic diet is also a myth. For some primitive societies, starchy fruits or starchy roots are a big part of their diet. In short, our paleolithic ancestors ate whatever nature provided.<\/p>\n

Myth #2: Our genetic makeup is hardwired around the \u201cpaleolithic diet\u201d<\/strong>.<\/span> In fact, humans are very adaptable. We are omnivores, which means we can eat whatever nature provides. We are designed to thrive in a wide variety of ecosystems. It is this adaptability that has allowed us to expand to every nook and cranny of the world.<\/p>\n

For example, the enzymes needed to digest grains are all inducible, which means the body can turn them on when needed. Our paleolithic ancestors may not have eaten much grain, but we can very quickly adapt to the introduction of grains into our diet. As I described above, for alpha-amylase this adaptation occurs through gene duplication.<\/p>\n

Myth #3: Our paleolithic ancestors were healthier than modern man<\/strong>:<\/span> It some respects, the paleolithic diet is healthy, as I mentioned above. However, we need to remember that our paleolithic ancestors rarely lived past 30 or 40. They simply did not live long enough to experience degenerative diseases like heart disease and cancer. We have no idea whether a diet that served our paleolithic ancestors well will keep us healthy into our 70s, 80s and beyond.<\/p>\n

How Was This Study Done?<\/strong><\/span><\/h2>\n

\"Clinical<\/a>This is a fascinating study, and one that would have been impossible just a few years ago. As I have described in previous issues of \u201cHealth Tips From the Professor\u201d, studies on our microbiome, the bacteria that inhabit our bodies, is a rapidly evolving area of research.<\/p>\n

When we talk about our microbiome, we generally think about our gut bacteria. However, the term \u201cmicrobiome\u201d includes all the bacteria that reside in our body, including those that reside in our oral mouth.<\/p>\n

And, like our gut bacteria, the species of bacteria that reside in our mouth are heavily dependent on the foods we eat. Specifically, there are three species of oral bacteria that thrive on starch. They possess an \u201camylase binding protein\u201d that allows them to capture salivary alpha-amylase and use it to break down dietary starch so they can use it as an energy source.<\/p>\n

Consequently, the abundance of these three bacterial species in the oral microbiome is a precise marker for the amount of starch in a person\u2019s diet.<\/strong><\/span> More importantly, high throughput DNA sequencing and supercomputers have made it simple to sequence all the bacteria in the oral microbiome and quantify the relative abundance of these three bacterial species.<\/p>\n

You are probably thinking, \u201cThat\u2019s fine, but how could you possibly determine the abundance of those bacteria in the mouth of a paleolithic human?\u201d Here is where it gets really interesting!<\/p>\n

The bacteria in our mouth form biofilms on our teeth, something we refer to as plaque. If the plaque remains on our teeth long enough, it calcifies, forming what is referred to as dental calculus (tooth tartar).<\/p>\n

In the modern world we remove dental biofilms by brushing after every meal. We remove dental plaque and tartar by semi-annual visits to the dentist. But these are recent developments. They are not something our ancestors did.<\/p>\n

Our ancestors simply accumulated dental calculus during their lifetime. More importantly, the dental calculus excluded air and water, so it preserved the DNA of the bacteria in their oral microbiome. That was the basis of the current study.<\/p>\n

The study was a collaboration of 50 scientists over a 7-year period. The scientists sequenced 124 oral microbiomes from humanoid species in Africa, including Neanderthals (430,000 to 40,000 years ago), Late Pleistocene (129,000 to 11,700 years ago) humans, and modern-day humans.<\/p>\n

Bacterial DNA from modern-day humans was obtained from dental calculus obtained during routine dental cleaning procedures by practicing dentists. The older DNA samples were obtained from dental calculus in the teeth of skeletal remains. The oldest DNA sample was obtained from a Neanderthal that lived around 100,000 years ago.<\/p>\n

For comparison they also obtained bacterial DNA from the dental calculus of chimpanzees and gorillas, man\u2019s closest primate relatives.<\/p>\n

The species of bacteria in the oral microbiome from all these samples were determined by high throughput sequences and computerized analysis using high speed supercomputers.<\/p>\n

Is The Paleo Diet Based On A Myth?<\/strong><\/span><\/h2>\n

\"Question<\/a>There were three important findings from this analysis:<\/p>\n

    \n
  1. The species of bacteria in the oral microbiome of Neanderthals and Late Pleistocene humans was much more diverse than for modern humans. This suggests that their diets were more diverse (perhaps depending on what foods were available in their environment), while modern diets have become more standardized.<\/li>\n<\/ol>\n

    2) The species of bacteria that thrive on starchy foods were remarkably constant in the oral microbiome of all human species from Neanderthals to Late Pleistocene humans to modern-day humans.<\/p>\n

    3) The species of bacteria that thrive on starchy foods were virtually absent from the oral microbiomes of our most closely related primates – chimpanzees and gorillas.<\/p>\n

    The authors concluded, \u201cThis \u2026 supports an early importance of starch-rich foods in Homo<\/em> evolution.\u201d<\/p>\n

    In other words, our paleolithic ancestors likely did eat starchy foods. Their diet may not have contained grains, rice, or beans in significant quantities. However, they consumed whatever starchy roots, fruits, and vegetables they could find.<\/p>\n

    So, is the Paleo diet based on a myth? It depends on how you phrase the question.<\/p>\n